[xen staging] tools/libxenstat: don't lose all VIFs when dom0 has no Linux bridge

[patchbot@xxxxxxx]

commit 0c53660c1cf34e9e7942c0b0f03bcfbc4fa801ab
Author:     Olivier Lambert <olivier.lambert@xxxxxxxxxx>
AuthorDate: Sat Oct 3 07:17:43 2026 +0000
Commit:     Anthony PERARD <anthony.perard@xxxxxxxxxx>
CommitDate: Mon Oct 12 17:31:39 2026 +0200

    tools/libxenstat: don't lose all VIFs when dom0 has no Linux bridge
    
    xenstat_collect_networks() looks for a Linux bridge (a
    /sys/class/net/*/bridge directory) so that, with bonding, dom0 can be
    given the bridge's counters. When there is none, as on hosts using Open
    vSwitch (the XCP-ng default), routed networking or only libvirt's
    virbr0 (which is excluded on purpose), getBridge() leaves devBridge
    empty. strstr(iface, "") then matches every interface, and devNoBridge
    is just "p", so every VIF with a standard name (vifN.M, vifN.M-emu)
    takes the bridge branch instead of being attached to its domain. Every
    domain ends up with zero networks, and xentop shows NETS 0.
    
    Only take the bridge branch when a bridge was actually found.
    
    Fixes: 1fd93d4f8cb8 ("xenstat: Linux dom0 statistics for case we use 
network bonding")
    Assisted-by: Claude-Code:claude-opus-5-5
    Signed-off-by: Olivier Lambert <olivier.lambert@xxxxxxxxxx>
    Tested-by: Jason Andryuk <jason.andryuk@xxxxxxx>
    Reviewed-by: Jason Andryuk <jason.andryuk@xxxxxxx>
    Acked-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
---
 tools/libs/stat/xenstat_linux.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/libs/stat/xenstat_linux.c b/tools/libs/stat/xenstat_linux.c
index b60e3fdcab..2a7d2f1a96 100644
--- a/tools/libs/stat/xenstat_linux.c
+++ b/tools/libs/stat/xenstat_linux.c
@@ -322,7 +322,8 @@ int xenstat_collect_networks(xenstat_node * node)
 
                /* If the device parsed is network bridge and both tx & rx 
packets are zero, we are most */
                /* likely using bonding so we alter the configuration for dom0 
to have bridge stats */
-               if ((strstr(iface, devBridge) != NULL) &&
+               if ((devBridge[0] != '\0') &&
+                   (strstr(iface, devBridge) != NULL) &&
                    (strstr(iface, devNoBridge) == NULL) &&
                    ((domain = xenstat_node_domain(node, 0)) != NULL)) {
                        for (i = 0; i < domain->num_networks; i++) {
--
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